Cuttlefish‐Inspired Self‐Adaptive Liquid Metal Network Enabling Electromagnetic Interference Shielding and Thermal Management

Abstract

With the refinement and miniaturization of integrated electronic devices, the requirements for stable operating temperature and antielectromagnetic interference are increasingly high. However, most of the current materials necessitate to develop the intelligent self‐adaptive regulation in response to external field stimuli to gratify the stipulations of different operating environments. Herein, cuttlefish‐inspired smart liquid metal based‐liquid crystal elastomer (LGN‐LCE) dual‐functional material enabling self‐adaptive electromagnetic wave interference shielding and thermal management is presented. Liquid crystal elastomer matrix endows the LGN‐LCE dynamic self‐morphing properties under thermal activation, which leads to the liquid metal network with tunable thermal/electrical conduction. The thermal conductivity of LGN‐LCE can be increased to 10.3 W m−1 K−1 with the rise of surrounding temperature, while the electrical conductivity of LGN‐LCE can be enhanced to 4.3 × 105 S m−1. Such promoted electrical conductivity helps strengthen electromagnetic interference (EMI) shielding performance of LGN‐LCE, and the minimum EMI shielding effectiveness of LGN‐LCE can be improved from 48 to 62 dB within the X‐band. This work may not only pave a new way to rationally design a self‐adaptive EMI shielding and thermal management systems, but also show good prospects for practical applications, including thermal management materials, EMI materials, flexible electronic materials, smart materials, artificial intelligence systems, biomedical, and aerospace applications.

Shear-Induced Fabrication of Cellulose Nanofibril/Liquid Metal Nanocomposite Films for Flexible Electromagnetic Interference Shielding and Thermal Management

“…30−33 It is worth noting that LM networks have also been proven to exhibit desired thermal behaviors and served as thermal/conductive pathways in composites. 29 Because the temperature rise of electronic systems can lead to a decrease in EMI shielding efficiency during electronic device operation, high thermal conductivity is a significant advantage for advanced electromagnetic shielding materials, 34 whereas the large cohesive energy inside LMs makes it difficult to disperse into smaller droplets. 35 In addition, after external force dispersion, LMs can rapidly spontaneously coalesce to form oxide shells (with a thickness of 0.5−3 nm), and the surface oxide shell combined with ligand coordination make them stably exist in polymer matrix.…”

“…In contrast, room-temperature liquid metals (LMs, e.g., a gallium and indium eutectic, also called EGaIn), serve as liquid conductive fillers and have received enormous attention due to their room-temperature fluidity, metallic conductivity, low toxicity, extreme deformability, and easy processability. − Nowadays, scholars have attempted to design LM composites with excellent conductivity for EMI shielding, including using decomposition agents (alkali bicarbonate) for LM foaming, coating LMs on the substrate, and introducing LMs into elastomers to fabricate porous and anisotropic composites. − It is worth noting that LM networks have also been proven to exhibit desired thermal behaviors and served as thermal/conductive pathways in composites . Because the temperature rise of electronic systems can lead to a decrease in EMI shielding efficiency during electronic device operation, high thermal conductivity is a significant advantage for advanced electromagnetic shielding materials, whereas the large cohesive energy inside LMs makes it difficult to disperse into smaller droplets . In addition, after external force dispersion, LMs can rapidly spontaneously coalesce to form oxide shells (with a thickness of 0.5–3 nm), and the surface oxide shell combined with ligand coordination make them stably exist in polymer matrix .…”